I made a kind of a ladder with 3 roosts on it at 3 heights. I first laid 2 pieces of 2x4 about 4'long about 4' apart for the base. Then i used increasing length 4x2 "up-struts" ( 1st pair are 12" high, then 20" high then the last is 28" high) on each base piece about 14 inches apart give or take. Then i used 2x2 for the roost pieces which I attached to the up struts with screws. Seems to work real well. Took about 10 mins to make and was made from off cut scraps so really cost basically nothing. My birds are on it constantly. I also put the height of the 3rd roost at the back at the same height as the window so they can look out while they are roosting.